Crusader King - Chapter 82: Wooden world(18)

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

I dedicated 10 years of my life, focusing solely on regression.[Authority: Death Regression has naturally been nullified.

Transmigrated to become a disciple of the demon sect, relying on the technique modifier to become a giant of the demon path.

[Detected the technique “Blood Nerve”, relying on devouring blood to cultivate]

[Side effect: easily affected by the spirit contained in the blood, becoming bloodthirsty, murderous, insane, and even brain dead]

[Please wait, system modification is in progress…]

[Ding! Modification completed and side effects canceled]

The Imperial Court of Tang Empire became dim and corrupt. The Emperor believed eunuchs. The officials vied with each other for authority. The Tang Empire was about to collapse. The flouring Confucianism, Buddhism and Taoism eyed it covetously. The three sects wanted to contend for the domination of the whole world. Which one would win in the end? Or would they coexist peacefully at last? Armies of different nations invaded the frontier on all sides. People and the whole world were in extreme misery. Who could save them?